Piloting a Patient Navigator Program for Weight Loss

Participants will be instructed to use a Withings wireless scale (stated accuracy to 0.1 kg) to weigh themselves. Participants will be instructed to step on the scale in the morning (before eating but after using the bathroom), wearing no shoes and minimal clothing, with the scale on a hard, flat, surface. Participants will be instructed to measure their weight for three consecutive days so that a participant's mean can be calculated at each time point in order to minimize the influence of daily fluctuations of weight. Data will be pulled from the Withings cloud to the study database via the Withings API. In order to maximize accuracy, we will remove errant weights (e.g., >1 kg change in 1 day).

The proportion of participants who have >5% weight loss (which is a standard threshold for clinical significance) will be a secondary outcome.

Data on recruitment rate will be available via REDCap. The benchmark is to enroll ~10 participants per month over the course of the 7-month recruitment period.

Data on retention will be available via REDCap. The benchmark is to retain a minimum of 75% of participants at 6 and 12 months.

Participants in the Navigator condition will be administered the Treatment Acceptability Questionnaire at 6 and 12 months, with content modified as needed to be clear that the items are referring to the navigator program, not any other weight loss intervention the participant may be receiving. This measure has six items, each rated on a 1-7 scale, with 7 being most positive. The benchmark of mean score of 5 or greater in the navigator condition was chosen based on face validity to correspond to ratings that are positive, as opposed to negative or neutral.

Attendance will be recorded in REDCap, so that the proportion of participants attending 4 or more sessions can be calculated (benchmark = 75%).

To assess the feasibility of navigators having fidelity to their assigned intervention approaches, a structured rubric will be created to code 10% of audio- or videorecorded sessions and 10% of emails. Sessions and emails will be randomly selected for review. The rubric will outline ratings for adhering to principles of the intervention approach as well as ratings for contamination. Each item in the rubric will be rated on a 1-10 scale, with 10 showing perfect fidelity. The benchmark of mean score of 8 or higher was chosen based on face validity.

A structured interview, conducted by a blinded member of the research staff, will query which types of weight change interventions have been utilized in the previous 6 months, as well as the length of intervention engagement. De-identified data will be coded. Each intervention reported by a participant will be categorized as a specific type of evidence-based intervention (nutritional counseling, behavioral counseling, select commercial programs, pharmacotherapy, or bariatric surgery) or a type of non-evidence-based intervention (e.g., self-guided weight loss attempt, use of herbal supplements, etc.). A categorical variable will capture whether or not the participant received an evidence-based intervention in the previous 6 months. A continuous measure also will indicate the number of weeks in the previous 6 months in which the the participant reported active use of an evidence-based intervention.

Semi-structured interviews (30 minutes each) will be conducted by trained team members at months 6 and 12 to inform improvements in the navigator program for future research. These qualitative data will be collected from 10 program participants in the Navigator condition. Participants will be purposively sampled across personal characteristics (e.g., age, gender), process (adherence, satisfaction), and outcome metrics (utilization of weight loss interventions, weight) to ensure diverse perspectives and insights. Interviews will explore a) acceptability of research and intervention procedures, and b) factors that hinder or facilitate adherence and weight loss.

Self-report information will be collected regarding age, race, ethnicity, sex, gender, income, education, insurance status, employment status, and marital status. These variables will be used for exploratory analyses.

All participants will complete a weight change history questionnaire developed by Myers et al. (2013) at BL.

A self-report checklist will ask if the participant has any of the following weight-related comorbidities: hypertension, type 2 diabetes or pre-diabetes, gastroesophageal reflux disease, arthritis, obstructive sleep apnea, heart disease including coronary artery disease or atrial fibrillation or heart failure, dyslipidemia (e.g., high cholesterol), non-alcoholic liver disease.

A series of questions developed by the study team will be administered to participants at BL only. These questions assess participant views regarding various evidence-based weight change treatments, and will ask participant to rank these treatments based on their long-term efficacy, accessibility, and trustworthiness with a ranking of 1 being the best, and a ranking of 6 being the worst.

A series of questions developed by Wharton et al. (2016) will be administered to all participants in the form of an online questionnaire at BL only. These questions will assess participant views and level of interest in evidence-based weight loss options i.e., bariatric surgery, anti-obesity medications, behavioral weight loss interventions, nutrition counseling, and commercial weight loss programs. Specifically, participants will be asked to report their level of interest in each treatment option on a scale from 1(Not interested) to 5(Very interested).

All participants will complete the Goal Ambivalence Scale (GAS) (Fadardi et al., 2022) at BL, 6 months, and 12 months. Participants will answer three questions assessing their readiness to lose weight on a scale from 1(Strongly disagree) to 4(Strongly agree). A lower score will indicate more ambivalence, whereas a higher score will indicate less ambivalence and more readiness.

A list of questions developed by Algarni et al. (2023) will be administered to all participants at BL, 6 months, and 12 months. Given the novelty of anti-obesity medications and the controversy surrounding their use and access, these questions will assess participant attitudes towards these medications. Participants will be asked to respond to six statements about weight management medications on a scale from 1(Disagree) to 3(Agree). A score between 8-15 indicates unfavorable attitudes towards weight management medications, while a score >16 indicates favorable attitudes.

All participants will be administered an adapted version of the Identification of Medication Adherence Barriers Questionnaire (IMAB-Q; Bhattacharya et al., 2023) at BL, 6 months and 12 months. These questions assess participant beliefs about consequences, emotions, and social influences related to medication adherence on a scale from 1(Strongly disagree) to 5(Strongly agree) with 1 indicating that the respondent did not consider the behavioural domain to be a barrier to adherence whilst 5 indicates that it is perceived to be a strong barrier.

All participants will complete the Motivation and attitudes towards changing health (MATCH) instrument at BL, 6 months, and 12 months. Participants will respond to statements measuring their willingness, ability, and how worthwhile it is for them to change their weight on a scale from 1(Strongly disagree) to 5(Strongly agree). A higher score indicates that participants are more willing, able, and feel its more worthwhile to change their weight.

All participants will complete the multidimensional trust in health care systems scale (Egede et al., 2008) at BL, 6 months, and 12 months. Participants will report their level of agreement with statements assessing their trust in health care institutions, health care providers, and health care payers on a scale from 1(Strongly disagree) to 5(Strongly agree). Higher total scores and higher subscale stores represent greater trust in health care systems.

A series of questions developed by Grannell et al. (2021) will be administered to participants at BL, 6 months, and 12 months. These questions will assess participant views on obesity, and participants will be asked to report how much they agree with these statements on a scale from 1(Completely disagree) to 5(Completely agree).

All participants will complete the AAHLS, developed by Chinn & McCarthy (2013) at BL, 6 months, and 12 months. These questions assess functional and critical health literacy on a scale from 1(Rarely) to 3(Often). Higher scores indicate greater health literacy.

Participants will be asked how confident they are in their ability to lose weight in the next 3 months on a scale from 1 (not at all confident) to 10 (very confident). This questions was adapted from Hoeppner et al. (2011)